A groundbreaking approach to monoclonal protein identification

For patients at risk of plasma cell disorders, early identification is critical to ensure better outcomes. Coined as MASS-FIX, our innovative approach uses matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and marks the first major breakthrough in multiple myeloma screening since gel electrophoresis was developed in 1967. 

By weighing M-proteins, we overcome electrophoresis’s limitations in detection and provide the most accurate understanding of a patient’s M-proteins. This novel testing also helps health care providers understand their patients’ risk of progression to multiple myeloma or amyloid light-chain (AL) amyloidosis. This level of insight is not possible with traditional testing methods. 

The impact of MASS-FIX extends beyond the hematologic systems into renal and neurologic spheres. As more is learned about the molecular, cytogenic, and protein variations of M-protein disorders, clinicians have discovered additional disease associations. Learn more here.

Now included in International Myeloma Working Group recommendations

  • MASS-FIX is now included in International Myeloma Working Group recommendations as an accepted method for screening of M-proteins.
  • MASS-FIX is included in International Myeloma Working Group recommendations as an accepted method for monitoring of M-protein-based diseases such as MGUS and multiple myeloma.

Superior testing for optimal patient care

The new MASS-FIX testing method provides: 

  • Best-in-class screening for multiple myeloma and early identification of myeloma relapse
  • Verifying if a patient’s IgG kappa mass is caused by monoclonal therapeutics or residual disease


  • Convenient, clinically relevant information, and industry-leading turnaround times for results 

Screening and diagnosis

DMOGA | Monoclonal Gammopathy, Diagnostic, Serum

Analytic time: 2 days  

Appropriate ordering scenario 

  • Assessing the risk of progression from MGUS to multiple myeloma 

PEISO | Protein Electrophoresis and Isotype, Serum

Analytic time: 2 days  

Appropriate ordering scenario 

  • Diagnosis of monoclonal gammopathies, when used in conjunction with serum free light-chain studies performed at client site 


TMOGA | Monoclonal Gammopathy, Monitoring, Serum

Analytic time: Same day/1 day 

Appropriate ordering scenario 

  • Determining if IgG kappa mass changes are caused by monoclonal therapeutics or residual disease 

MALD | M-Protein Isotype, Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry, Serum

Analytic time: Same day/1 day 

Appropriate ordering scenario 

  • When protein electrophoresis and free light-chain testing is performed in house; M-protein isotyping by MASS-FIX only 

How an ex-NFL linebacker overcame his greatest opponent, amyloidosis

Matt Millen, an ex-pro NFL player who played on four Super Bowl-winning teams, underwent a nearly six-year medical journey in search for answers. Finally, he was diagnosed with amyloidosis using a new testing methodology at Mayo Clinic.

Learn more about how to order this evaluation at your institution.

Additional resources

Publications from Mayo Clinic

  • Abeykoon JP, Murray DL, Murray I, et al. Implications of detecting serum monoclonal protein by MASS‐fix following stem cell transplantation in multiple myeloma. Br J Haematol. 2020 Nov. 
  • Dispenzieri A, Larson DR, Rajkumar SV, Kyle RA, Kumar SK, Kourelis T, Arendt B, Willrcih M, Dasari S, Murray D. N-glycosylation of monoclonal light chains on routine MASS-FIX testing is a risk factor for MGUS progression. Leukemia. 2020 Oct;34(10):2749-2753.
  • Kourelis T, Murray DL, Dasari S, et al. MASS-FIX may allow identification of patients at risk for light chain amyloidosis before the onset of symptoms. Am J Hematol. 2018;93(11):368-E370.   
  • Kumar S, Murray D, Dasari S, et al. Assay to rapidly screen for immunoglobulin light chain glycosylation: a potential path to earlier AL diagnosis for a subset of patients. Leukemia. 2018 Jan;33(1):254-257. 
  • Mellors P, Binder M, Ketterling R, et al. Metaphase cytogenetics and plasma cell proliferation index for risk stratification in newly diagnosed multiple myeloma. Blood Adv. 2020 May;4(10):2236-2244. 
  • Milani P, Murray DL, Barnidge DR, et al. The utility of MASS-FIX to detect and monitor monoclonal proteins in the clinic. Am J Hematol. 2017;92:772-779.  
  • Mills JR, Barnidge DR, Dispenzieri A, and Murray DL. High sensitivity blood-based M-protein detection in sCR patients with multiple myeloma. Blood Cancer J. 2017;7(590).
  • Mills JR, Kohlhagen MC, Dasari S, et al. Comprehensive assessment of  M-proteins using nanobody enrichment coupled to MALDI-TOF mass spectrometry. Clin Chem. 2016 Oct;62(10):1334-1344. 
  • Mills JR,  Kohlhagen MC, Willrich MAV, et al. A universal solution for eliminating false positives in myeloma due to therapeutic monoclonal antibody interference. Blood. 2018 Aug;132(6):670-672. 
  • Murray, D.L., Puig, N., Kristinsson, S. et al. Mass spectrometry for the evaluation of monoclonal proteins in multiple myeloma and related disorders: an International Myeloma Working Group Mass Spectrometry Committee Report. Blood Cancer J. 2021:11 (24).